Samacheer Kalvi Class 12 Chemistry Solutions Chapter 15 Chemistry in Everyday Life

Part - I Text Book Evaluation

I. Choose the Correct Answer

Question 1. Which of the following is an antipyretic?
(a) Streptomycin
(b) Chloromycetin
(c) Asprin
(d) Penicillin
Answer: (c) Asprin
In simple words: Aspirin is a medicine that helps to lower fever and reduce pain in the body.

🎯 Exam Tip: Remember common names for drugs and their classifications (e.g., antipyretic for fever, analgesic for pain) as these are frequently tested.

Question 2. Dettol is the mixture of
(a) Chloroxylenol and bithionol
(b) Chloroxylenol and a-terpineol
(c) phenol and iodine
(d) terpineol and bithionol
Answer: (b) Chloroxylenol and a-terpineol
In simple words: Dettol is made from mixing two main chemicals: chloroxylenol and a-terpineol. This mixture helps it to kill germs.

🎯 Exam Tip: Knowing the key active ingredients of common antiseptics and disinfectants is essential for multiple-choice questions.

Question 3. Antiseptics and disinfectants either kill or prevent growth of microorganisms. Identify which of the following statement is not true.
(a) dilute solutions of boric acid and hydrogen peroxide are strong antiseptics.
(b) Disinfectants harm the living tissues.
(c) A 0.2% solution of phenol is an antiseptic while 1% solution acts as a disinfectant.
(d) Chlorine and iodine are used as strong disinfectants.
Answer: (a) dilute solutions of boric acid and hydrogen peroxide are strong antiseptics.
In simple words: Antiseptics and disinfectants are substances that stop or kill tiny living things like germs. The statement that is not true is that weak solutions of boric acid and hydrogen peroxide are *strong* antiseptics; they are actually quite mild.

🎯 Exam Tip: Pay close attention to keywords like "strong" or "weak" and "not true" in questions, as they can change the correct answer significantly.

Question 4. manufactured from
(a) cellulose
(b) toluene
(c) cyclohexene
(d) starch
Answer: (b) toluene
In simple words: Toluene is a chemical that can be made from certain processes and is used to make other substances.

🎯 Exam Tip: For synthesis-related questions, recognize common starting materials or end products for key compounds.

Question 5. Drugs that bind to the receptor site and inhibit its natural function are called
(a) antagonists
(b) agonists
(c) enzymes
(d) molecular targets
Answer: (a) antagonists
In simple words: Medicines that connect to a specific spot in the body (receptor) and stop it from working as it normally would are called antagonists.

🎯 Exam Tip: Distinguish clearly between agonists (which activate receptors) and antagonists (which block receptors).

Question 6. Aspirin is a/an
(a) acetylsalicylic acid
(b) benzoyl salicylic acid
(c) chlorobenzoic acid
(d) anthranilic acid
Answer: (a) acetylsalicylic acid
In simple words: Aspirin is also known by its chemical name, acetylsalicylic acid.

🎯 Exam Tip: Learn the chemical names for common medicines, as they are often used in exams instead of brand names.

Question 7. Which one of the following structures represents nylon 6,6 polymer?
(a) [Structure (a)]
(b) [Structure (b)]
(c) [Structure (c)]
(d) [Structure (d)]
Answer: (d) [Structure (d)]
In simple words: Nylon 6,6 is a type of polymer known for its strong fiber properties. Its structure consists of repeating units of hexamethylenediamine and adipic acid.

🎯 Exam Tip: For polymer structure questions, practice identifying the repeating monomer units and the type of linkage (e.g., amide for nylon).

Question 8. Natural rubber has
(a) alternate cis- and trans-configuration
(b) random cis- and trans-configuration
(c) all cis-configuration
(d) all trans-configuration
Answer: (c) all cis-configuration
In simple words: Natural rubber always has a specific shape called 'all cis-configuration'. This structure gives it its stretchy and elastic properties.

🎯 Exam Tip: Remember that the stereochemistry (cis- or trans-configuration) is crucial for the physical properties and classification of polymers like rubber.

Question 9. Nylon is an example of
(a) polyamide
(b) polythene
(d) poly saccharide
Answer: (a) polyamide
In simple words: Nylon is a type of polymer known as a polyamide, which means it's made from many amide units linked together.

🎯 Exam Tip: Classify polymers based on their repeating units and the types of bonds formed (e.g., polyamides contain amide links, polyesters contain ester links).

Question 10. Terylene is an example of
(a) polyamide
(b) polythene
(c) polyester
(d) polysaccharide
Answer: (c) polyester
In simple words: Terylene is a kind of polymer called a polyester, which is used to make strong fibers and fabrics.

🎯 Exam Tip: Recognize common polymers like Terylene and their classifications to answer questions about their type or usage.

Question 11. Which is the monomer of neoprene in the following?
(a) \( \text{CH}_2 = \text{C}(\text{Cl}) - \text{CH} = \text{CH}_2 \)
(b) \( \text{CH}_2 = \text{CH} - \text{C} \equiv \text{CH} \)
(c) \( \text{CH}_2 = \text{CH} - \text{CH} = \text{CH}_2 \)
(d) \( \text{CH}_2 = \text{C}(\text{CH}_3) - \text{CH} = \text{CH}_2 \)
Answer: (a) \( \text{CH}_2 = \text{C}(\text{Cl}) - \text{CH} = \text{CH}_2 \)
In simple words: Neoprene is a type of synthetic rubber. Its basic building block, called a monomer, is chloroprene, which has a chlorine atom and two double bonds in its structure.

🎯 Exam Tip: Memorize the monomers of important synthetic rubbers and plastics, especially for drawing or identifying structures.

Question 12. Which one of the following is a biodegradable polymer?
(a) HDPE
(c) Nylon 6
(d) PHBV
Answer: (d) PHBV
In simple words: A biodegradable polymer is one that can break down naturally in the environment. Among the choices, PHBV (Polyhydroxybutyrate-co-hydroxyvalerate) is an example of such a polymer.

🎯 Exam Tip: Focus on understanding the environmental significance of biodegradable polymers and their common examples.

Question 13. Non stick cook wares generally have a coating of a polymer, whose monomer is
(a) ethane
(b) prop-2-enenitrile
(c) chloroethene
(d) 1,1,2,2-tetrafluoroethane
Answer: (d) 1,1,2,2-tetrafluoroethane
In simple words: Non-stick pans are coated with a special plastic called Teflon. The tiny units that build this plastic (monomer) are called 1,1,2,2-tetrafluoroethane.

🎯 Exam Tip: Connect common household materials to their chemical composition and the monomers from which they are formed.

Question 14. Assertion : 2-methyl-1,3-butadiene is the monomer of natural rubber Reason: Natural rubber is formed through anionic addition polymerisation.
(a) If both assertion and reason are true and reason is the correct explanation of assertion.
(b) if both assertion and reason are true but reason is not the correct explanation of assertion.
(c) assertion is true but reason is false.
(d) both assertion and reason are false.
Answer: (c) assertion is true but reason is false.
In simple words: The first statement (Assertion) is correct: 2-methyl-1,3-butadiene is indeed the monomer of natural rubber. However, the second statement (Reason) is false because natural rubber forms through free radical addition polymerisation, not anionic addition polymerisation.

🎯 Exam Tip: For assertion-reason questions, carefully evaluate the truth of both statements individually before assessing the correctness of the reason.

Question 15. Which of the following is a drug?
(a) novestrol
(b) seldane
(c) salvarsan
(d) Chioramphenicol
Answer: (a) novestrol
In simple words: Novestrol is a synthetic drug, often used as an antifertility agent. It helps in controlling reproductive functions.

🎯 Exam Tip: Keep a mental list of common drug names and their primary classifications or uses to quickly identify them.

Question 16. The drug used to induce sleep is
(a) paracetamol
(b) bithional
(c) chloroquine
(d) equanil
Answer: (d) equanil
In simple words: Equanil is a medicine that is used to help a person sleep or calm down, often prescribed for anxiety or insomnia.

🎯 Exam Tip: Understand the specific applications of different drugs, such as which ones are used as tranquilizers or sedatives.

Question 17. Which of the following is a co-polymer?
(a) Orlon
(b) PVC
(c) Teflon
(d) PHBV
Answer: (d) PHBV
In simple words: A co-polymer is a polymer made from two or more different types of monomers (small units). PHBV (Polyhydroxybutyrate-co-hydroxyvalerate) is an example of a co-polymer, made from two different hydroxy acids.

🎯 Exam Tip: Clearly differentiate between homopolymers (made of one type of monomer) and copolymers (made of two or more types).

Question 18. The polymer used in making blankets (artificial wool) is
(a) polystyrene
(b) PAN
(c) polyester
(d) polythene
Answer: (b) PAN
In simple words: Blankets and artificial wool are made from polymers like PAN (Polyacrylonitrile). It is chosen for its soft, warm, and wool-like feel.

🎯 Exam Tip: Link common polymer applications (e.g., artificial wool) to their corresponding polymer names and properties.

Question 19. Regarding cross-linked or network polymers, which of the following statement is incorrect? (NEET)
(a) Examples are Bakelite and melamine
(b) They are formed from bi and tri-functional monomers
(c) They contain covalent bonds between various linear polymer chains
(d) They contain strong covalent bonds in their polymer chain
Answer: (d) They contain strong covalent bonds in their polymer chain
In simple words: Cross-linked polymers have a network structure formed by strong bonds *between* different polymer chains, not necessarily just *within* one single chain. So, the statement saying they contain strong covalent bonds *in their* polymer chain is incorrect in the context of network structures.

🎯 Exam Tip: For questions about polymer types, focus on the nature and location of the bonds (inter-chain vs. intra-chain) and their effect on structure.

Question 20. A mixture of chloroxylenol and terpineol acts as (NEET)
(a) antiseptic
(b) antipyretic
(c) antibiotic
(d) analgesic
Answer: (a) antiseptic
In simple words: A mix of chloroxylenol and terpineol works as an antiseptic, which means it can prevent the growth of germs on living tissues or surfaces.

🎯 Exam Tip: Remember that combinations of chemicals can have specific actions, and common antiseptic mixtures often feature in exams.

II. Short Answer

Question 1. Which chemical is responsible for the antiseptic properties of Dettol.
Answer: Chloroxylenol and terpineol are the chemicals in Dettol that give it antiseptic properties. Among these, chloroxylenol plays a more important role in killing germs. These two ingredients combined create a powerful formula to fight bacteria and viruses on surfaces and skin. Chloroxylenol is used for skin cleaning and to disinfect surgical instruments.
In simple words: Chloroxylenol and terpineol are the main chemicals in Dettol that make it an antiseptic, helping to kill germs.

🎯 Exam Tip: For specific product questions, identify the primary active ingredient and its function rather than just listing all components.

Question 2. What are antibiotics?
Answer: Antibiotics are special medicines that have the ability to kill harmful pathogenic bacteria in the body or stop them from growing. They are crucial for treating bacterial infections, but do not work against viruses. Examples include amoxicillin and cefixime.
In simple words: Antibiotics are medicines used to kill bacteria or stop them from growing, helping to cure infections.

🎯 Exam Tip: Always remember that antibiotics target bacteria and are ineffective against viral infections.

Question 3. Name one substance which can act as both analgesic and antipyretic
Answer: Aspirin (acetylsalicylic acid) is a chemical substance that can reduce both body temperature (fever) and pain. This means it acts as both an antipyretic and an analgesic. Its dual action makes it a common ingredient in many over-the-counter cold and flu medications.
In simple words: Aspirin is a medicine that helps lower fever (antipyretic) and also reduces pain (analgesic).

🎯 Exam Tip: Know common drugs that have multiple therapeutic effects, and be ready to name them. Aspirin is a classic example.

Question 4. Write a note on synthetic detergents.
Answer: Synthetic detergents are cleaning agents that are formulated products containing either sodium salts of alkyl hydrogen sulphates or sodium salts of long chain alkyl benzene sulphonic acids. They are different from soap and can clean well even in hard water without forming scum. Unlike traditional soaps, detergents do not form scum in hard water, making them very effective for washing clothes and dishes. There are three main types:

🎯 Exam Tip: Focus on the chemical composition and key advantage (working in hard water) of synthetic detergents compared to soaps, and know their main classifications.

Question 5. How do antiseptics differ from disinfectants?
Answer: Antiseptics and disinfectants both aim to reduce microorganisms, but they differ in their application:

🎯 Exam Tip: Clearly differentiate between the application (living tissue vs. inanimate objects) and strength of antiseptics and disinfectants.

Question 6. What are food preservatives?
Answer: Food preservatives are chemical substances added to food to stop tiny living things (microorganisms) from spoiling it. They can prevent or slow down fermentation, acidification, or other types of food decomposition. These additives are vital in modern food production to extend shelf life and prevent foodborne illnesses. Common examples include: 1. Acetic acid, primarily used to preserve pickles. 2. Sodium metabisulphite, used for fresh vegetables and fruits. 3. Sodium benzoate, commonly used in juices.
In simple words: Food preservatives are chemicals that keep food from spoiling by stopping microorganisms from growing, helping it stay fresh for longer.

🎯 Exam Tip: Understand the purpose of food preservatives (inhibiting microbial growth) and be able to provide specific examples and their applications.

Question 7. Why do soaps not work in hard water?
Answer: Soaps don't work well in hard water because hard water contains calcium and magnesium ions. When soaps are dissolved in hard water, these calcium and magnesium ions displace the sodium or potassium ions from the soap. This reaction forms insoluble calcium or magnesium salts of fatty acids, which appear as a solid, sticky substance called scum. This chemical reaction reduces the soap's ability to create lather and effectively remove dirt. Therefore, soaps do not work effectively in hard water.
In simple words: Soaps don't work well in hard water because the minerals in the water react with the soap to form a solid "scum" that can't clean.

🎯 Exam Tip: Focus on the chemical reaction between metal ions in hard water and the soap molecules, leading to the formation of insoluble scum.

Question 8. What are drugs? How are they classified?
Answer: A drug is a substance used to modify or explore physiological systems or pathological states for the benefit of the recipient. It is used for the purpose of diagnosis, prevention, cure, or relief of a disease. Understanding these classifications helps scientists develop new medicines that target specific ailments more effectively.
Drugs are classified based on several criteria:
1. Classification based on chemical structure: Drugs with a common chemical backbone are grouped together. For example, ampicillin and amoxicillin are part of the penicillin group because they have similar structures. While structurally similar compounds often share chemical properties, their biological actions might differ.
2. Classification based on pharmacological effect: This method groups drugs based on their biological effect on the recipient. For example, medicines that kill pathogenic bacteria are classified as antibiotics. This grouping provides a range of drugs for a particular disease.
3. Classification based on the target system: Drugs are grouped by the specific biological system or process they target. For instance, antibiotics like streptomycin and erythromycin inhibit protein synthesis in bacteria, thus targeting that bacterial process. This classification is often more specific than pharmacological classification.
4. Classification based on the site of action: This classification groups drugs based on where they act. Drug molecules interact with specific biomolecules like enzymes or receptors, which are called drug targets. Classifying drugs by their target allows for highly specific treatments, as compounds with a common mechanism of action will target the same site.
In simple words: Drugs are substances that change how our body works to treat or prevent diseases. They can be grouped by their chemical makeup, what effects they have, which part of the body they target, or exactly where they act inside the body.

🎯 Exam Tip: For drug classification, define "drug" first, then clearly explain each classification method with a relevant example for full marks.

Question 9. How the tranquilizers work in body.
Answer: Tranquilizers are neurologically active drugs that act on the central nervous system. They work by blocking the neurotransmitter dopamine in the brain, which helps to calm the body and reduce anxiety. By modulating brain activity, tranquilizers are used to manage anxiety disorders and certain mental health conditions. Examples of major tranquilizers include Haloperidol and Clozapine, while minor tranquilizers include Diazepam (Valium) and Alprazolam.
In simple words: Tranquilizers calm the body by blocking a brain chemical called dopamine in the central nervous system.

🎯 Exam Tip: Focus on the key neurotransmitter (dopamine) and the mechanism (blocking) when explaining how tranquilizers work.

Question 10. Write the structural formula of aspirin. Structural formula of aspirin : (Acetyl Salicylic Acid) \( \text{C}_9\text{H}_8\text{O}_4 \)
Answer: The structural formula of aspirin (Acetyl Salicylic Acid) is shown below. It has a chemical formula of \( \text{C}_9\text{H}_8\text{O}_4 \). This particular arrangement of atoms gives aspirin its well-known pain-relieving and anti-inflammatory properties.
\[ \text{C}_9\text{H}_8\text{O}_4 \]

Structural representation of Aspirin:

🎯 Exam Tip: Practice drawing the full structural formula of aspirin and other important organic compounds, ensuring all bonds and atoms are correctly placed.

Question 11. Explain the mechanism of cleansing action of soaps and detergents
Answer: The cleansing action of soaps and detergents is related to their unique structure, which exhibits dual polarity. For example, sodium palmitate is a common soap. The molecules of soaps and detergents have two distinct parts:
1. Hydrocarbon portion: This part is non-polar and hydrophobic (water-hating). It is soluble in oils and greases but not in water.
2. Carboxyl portion: This part is polar and hydrophilic (water-loving). It is soluble in water.

When soap is added to water containing dirt or grease (which is often oily), the non-polar hydrocarbon part of the soap molecule attaches to the oily or greasy dirt particles. At the same time, the polar carboxylate end of the soap molecule remains attracted to water. As a result, the soap molecules surround the oil/grease droplets, forming tiny spheres called micelles, with the oil-loving tails pointing inwards and the water-loving heads pointing outwards. This unique dual nature allows them to emulsify fats and oils, effectively lifting dirt from surfaces.

These micelles do not combine into larger drops because their surfaces are all negatively charged and repel each other. The water-loving outer surface of the micelles then allows the oil and dirt particles to be suspended in water and easily washed away. The cleansing action of detergents is similar to that of soaps, as they also act as emulsifying agents between water and water-insoluble greases.
In simple words: Soaps and detergents clean because they have a special shape with two ends: one loves water and one loves oil. The oil-loving part sticks to dirt and grease, and the water-loving part then lets water wash the dirt away in tiny balls called micelles. This helps remove stains and clean surfaces.

🎯 Exam Tip: When explaining cleansing action, ensure you describe both the dual polarity (hydrophobic/hydrophilic parts) of soap molecules and the formation of micelles.

Question 12. Which sweetening agent are used to prepare sweets for a diabetic patient?
Answer: Artificial sweetening agents like saccharin, alitame, and aspartame are used to make sweets for diabetic patients. These agents provide sweetness without raising blood sugar levels.
In simple words: Diabetics can eat sweets made with special sugar substitutes like saccharin and aspartame, which give sweetness without using real sugar.

🎯 Exam Tip: Remember common artificial sweeteners like saccharin, aspartame, and alitame, and their use for diabetic patients.

Question 13. What are narcotic and non – narcotic drugs. Give examples.
Answer:

🎯 Exam Tip: Clearly distinguish between the pain relief mechanism, addictive nature, and specific examples for both narcotic and non-narcotic drugs.

Question 14. What are anti-fertility drugs? Give examples.
Answer: Anti-fertility drugs are chemical substances that stop the action of hormones which promote pregnancy. These drugs help reduce the chances of pregnancy and act as a protective measure. They are made from synthetic progesterone derivatives or a mix of oestrogen and progesterone derivatives. These drugs help control family size safely. Examples include Ethynylestradiol, Menstranol, and Norcthynodrel.
In simple words: Anti-fertility drugs are medicines that stop hormones from causing pregnancy. They help prevent unwanted pregnancies and include substances like Ethynylestradiol.

🎯 Exam Tip: Focus on the purpose (suppressing pregnancy), the type of hormones they affect (progesterone, oestrogen), and at least two examples.

Question 15. Write a note on copolymer.
Answer: A copolymer is a polymer made from two or more different kinds of monomer units. For example, SBR rubber (Buna-S) is a copolymer that contains styrene and butadiene monomer units. Copolymers have properties that are quite different from homopolymers, which are made from only one type of monomer. This mixing of monomers allows for a wide range of material properties. A mixture of styrene and 1,3-butadiene forms a copolymer called Buna-S.
In simple words: A copolymer is a special type of plastic made by joining two or more different small molecules (monomers). SBR rubber is an example, made from styrene and butadiene.

🎯 Exam Tip: Define copolymer as a polymer from two or more distinct monomers and provide SBR rubber as a clear example, mentioning its constituent monomers.

Question 16. What are biodegradable polymers? Give examples.
Answer: Biodegradable polymers are materials that can be easily broken down by tiny living organisms (microorganisms) in the environment. Unlike synthetic polymers, which stay in the environment for a long time, natural polymers degrade on their own after a certain period. Biopolymers naturally break down in living systems over time through enzymatic hydrolysis and some oxidation. This helps reduce pollution and waste. Examples include Polyhydroxybutyrate (PHB), Polyhydroxybutyrate-co-hydroxyl valerate (PHBV), and Polylactic acid (PLA).
In simple words: Biodegradable polymers are materials that nature can break down using tiny living things, like bacteria. PHB and PLA are good examples of these eco-friendly materials.

🎯 Exam Tip: Ensure you define them as materials decomposed by microorganisms and provide at least two common examples like PHB or PLA.

Question 17. How is terylene prepared?
Answer: Terylene is prepared through a process called condensation polymerization. The monomers used are ethylene glycol and terephthalic acid (or dimethyl terephthalate). A catalyst like zinc acetate or antimony trioxide is used to help the reaction. The product formed is Terylene, which is a polyester. This reaction forms a strong, durable polymer used in many fabrics.
In simple words: Terylene is made by joining ethylene glycol and terephthalic acid using a special chemical helper (catalyst). The final product is a type of plastic called polyester.

🎯 Exam Tip: State that terylene is a condensation polymer, list the two main monomers (ethylene glycol and terephthalic acid), and mention a catalyst if you remember one.

Question 18. Write a note on vulcanization of rubber
Answer:
1. Natural rubber is normally very soft and sticky. It absorbs a lot of water and has low tensile strength, meaning it stretches easily and breaks. Its properties can be greatly improved by a process called vulcanization.
2. In vulcanization, natural rubber is mixed with 3-5% sulfur and then heated between 100-150°C. This heating causes the sulfur atoms to form cross-links (disulfide bonds, -S-S-) between the cis-1,4-polyisoprene chains of the rubber. These new bonds make the rubber much stronger.
3. The final physical properties of the rubber can be changed by controlling how much sulfur is used. If 3 to 10% sulfur is added, the resulting rubber becomes harder but remains flexible.
4. This process makes rubber more durable, elastic, and resistant to temperature changes. It significantly improves its practical applications.
In simple words: Vulcanization is a process where natural rubber is heated with sulfur. This makes the rubber much stronger, more elastic, and less sticky, making it useful for things like tires.

🎯 Exam Tip: Explain vulcanization as heating rubber with sulfur to form cross-links, improving its strength and elasticity. Mention improved properties like water resistance and tensile strength.

Question 19. Regarding cross-linked or network polymers, which of the following statement is incorrect? (NEET)
(a) Examples are Bakelite and melamine
(b) They are formed from bi and tri-functional monomers
(c) They contain covalent bonds between various linear polymer chains
(d) They contain strong covalent bonds in their polymer chain
Answer: (d) They contain strong covalent bonds in their polymer chain
In simple words: The wrong statement is that cross-linked polymers have strong covalent bonds *only* within their main polymer chain; in fact, they have strong bonds *between* chains, forming a network.

🎯 Exam Tip: Remember that cross-linked polymers are characterized by extensive covalent bonding *between* polymer chains, forming a rigid 3D network, not just strong bonds within a single chain.

Question 20. Differentiate thermoplastic and thermosetting plastics.
Answer:

🎯 Exam Tip: Remember the key difference: thermoplastics can be remoulded, while thermosetting plastics cannot. Provide examples for each type.

12th Chemistry Guide Chemistry in Everyday Life Additional Questions and Answers

Part – II – Additional Questions

I. Choose the best answer

Question 1. An ideal drug is the one which is
(i) non-toxic
(ii) bio-compatible
(iii) bio-degradable
(iv) should not have any side effects.
(a) (i) & (ii)
(b) (i) & (iii)
(c) (i), (ii) & (iv)
(d) (i), (ii), (iii) & (iv)
Answer: (d) (i), (ii), (iii) & (iv)
In simple words: An ideal drug should be safe, work well with the body, break down easily after use, and have no bad side effects. All listed options are true for an ideal drug.

🎯 Exam Tip: When considering ideal drug properties, remember it must be effective, safe, not harmful, and should eventually be processed by the body.

Question 2. A drug is safer when its therapeutic index is
(a) lower
(b) higher
(c) one
(d) zero
Answer: (b) higher
In simple words: A drug is safer when its therapeutic index is higher, meaning there's a wider range between the amount that helps and the amount that harms.

🎯 Exam Tip: A higher therapeutic index means a larger difference between the effective dose and the toxic dose, indicating a safer drug.

Question 3. Which among the following belongs to the group penicillin?
(a) Ampicillin
(b) Amoxicillin
(c) Methicillin
(d) All of the options
Answer: (d) All of the options
In simple words: Ampicillin, Amoxicillin, and Methicillin are all types of antibiotics that belong to the penicillin family.

🎯 Exam Tip: Penicillins are a broad class of antibiotics; be familiar with common examples like Ampicillin and Amoxicillin.

Question 4. Which among the following is an antibiotic?
(a) Atenolol
(b) Cefixime
(c) Amlodipine
(d) All of the options
Answer: (b) Cefixime
In simple words: Cefixime is an antibiotic, which is a type of medicine used to fight bacterial infections.

🎯 Exam Tip: Know common examples of antibiotics; Cefixime is a third-generation cephalosporin antibiotic.

Question 5. Which among the following is an anti-hypertensive drug?
(a) Ampicillin
(b) Cefixime
(c) Atenolol
(d) Cefpodoxime
Answer: (c) Atenolol
In simple words: Atenolol is a drug used to lower high blood pressure.

🎯 Exam Tip: Anti-hypertensive drugs help manage high blood pressure; Atenolol is a beta-blocker often used for this purpose.

Question 6. Proteins which act as biological catalysts are called.
(a) Antibiotics
(b) Enzymes
(c) Tranquilizers
(d) Analgesics
Answer: (b) Enzymes
In simple words: Enzymes are special proteins in our body that speed up chemical reactions, like digestion.

🎯 Exam Tip: Understand that enzymes are biological catalysts, essential for most biochemical reactions in living organisms.

Question 7. Penicillin is an example of
(a) Analgesics
(b) Antibiotic
(c) Anaesthetic
(d) Antacid
Answer: (b) Antibiotic
In simple words: Penicillin is a well-known antibiotic used to treat bacterial infections.

🎯 Exam Tip: Penicillin is a classic example of an antibiotic, a substance that kills or inhibits the growth of bacteria.

Question 8. Drugs which act on the central nervous system by blocking the neurotransmitter
(a) Analgesics
(b) Antacids
(c) Tranquilizers
(d) Antihistamines
Answer: (c) Tranquilizers
In simple words: Tranquilizers are drugs that affect the brain's signals to help calm a person down.

🎯 Exam Tip: Tranquilizers primarily act on the central nervous system, often by blocking neurotransmitters, to reduce anxiety and induce calmness.

Question 9. Diazepam is an example of
(a) analgesics
(b) antacids
(c) tranquilizer
(d) antihistamine
Answer: (c) tranquilizer
In simple words: Diazepam is a type of tranquilizer, used to reduce anxiety and help with sleep.

🎯 Exam Tip: Diazepam (Valium) is a benzodiazepine, a well-known tranquilizer used for anxiety, insomnia, and muscle spasms.

Question 10. Which among the following is not a non-narcotic analgesic?
(a) Aspirin
(b) Ibuprofen
(c) Acetaminophen
(d) Morphine
Answer: (d) Morphine – A narcotic analgesic
In simple words: Morphine is a strong narcotic painkiller, unlike aspirin or ibuprofen, which are non-narcotic.

🎯 Exam Tip: Remember that morphine is a powerful opioid, classified as a narcotic analgesic, while aspirin, ibuprofen, and acetaminophen are non-narcotic pain relievers.

Question 11. Which among the following is an inhalational general anesthetics?
(a) lidocaine
(b) Isoflurane
(c) Propofol
(d) Procaine
Answer: (b) Isoflurane
In simple words: Isoflurane is a gas that is breathed in to make someone completely unconscious for surgery.

🎯 Exam Tip: Inhalational general anesthetics are administered as gases to induce and maintain general anesthesia; Isoflurane is a common example.

Question 12. Which among the following is used as an antacid?
(a) Sodium hydroxide
(b) Potassium hydroxide
(c) Aluminium hydroxide
(d) Calcium carbonate
Answer: (c) Aluminium hydroxide
In simple words: Aluminium hydroxide is a common ingredient in antacids, medicines that reduce stomach acid.

🎯 Exam Tip: Antacids are bases that neutralize stomach acid; common examples include aluminum hydroxide and magnesium hydroxide.

Question 13. The drugs which provide relief from allergic effects are called.
(a) Antimicrobials
(b) Antacids
(c) Opioids
(d) Antihistamines
Answer: (d) Antihistamines
In simple words: Antihistamines are medicines that help stop allergy symptoms like itching and sneezing.

🎯 Exam Tip: Antihistamines are crucial for treating allergic reactions by blocking histamine receptors, reducing symptoms like itching, sneezing, and runny nose.

Question 14. Neomycin belongs to
(a) beta-lactams
(b) aminoglycosides
(c) tetracyclines
(d) macrolides
Answer: (b) aminoglycosides
In simple words: Neomycin is an antibiotic that belongs to the group of medicines called aminoglycosides.

🎯 Exam Tip: Classify common antibiotics by their group; Neomycin is a well-known aminoglycoside.

Question 15. Benzalkonium chloride is used as an
(a) disinfectant
(b) antibiotic
(c) antiseptic
(d) antifertility drug
Answer: (c) antiseptic
In simple words: Benzalkonium chloride is a chemical used to kill germs on living tissues, making it an antiseptic.

🎯 Exam Tip: Antiseptics are applied to living tissues to prevent infection, while disinfectants are used on inanimate objects. Benzalkonium chloride is an antiseptic.

Question 16. Which drug suppresses ovulation/fertilisation?
(a) Oxytetracycline
(b) Terfenadine
(c) Menstranol
(d) Minocycline
Answer: (c) Menstranol
In simple words: Menstranol is a drug that helps prevent pregnancy by stopping ovulation.

🎯 Exam Tip: Antifertility drugs like Menstranol work by interfering with the reproductive cycle, often by suppressing ovulation.

Question 17. The drug which inhibits bacterial cell wall synthesis is
(a) macrolide
(b) beta-lactams
(c) fluoroquinolone
(d) tetracycline
Answer: (b) beta-lactams
In simple words: Beta-lactam drugs, like penicillin, stop bacteria from building their cell walls, which kills them.

🎯 Exam Tip: Beta-lactam antibiotics (e.g., penicillins, cephalosporins) are known for their mechanism of inhibiting bacterial cell wall synthesis.

Question 18. The drug which targets bacterial ribosomes and prevents protein production is
(a) macrolide
(b) beta-lactam
(c) fluoroquinolone
(d) tetracycline
Answer: (a) macrolide
In simple words: Macrolide drugs work by stopping bacteria from making new proteins, which they need to grow and multiply.

🎯 Exam Tip: Understand that macrolides inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit, a key mechanism of action for this class of antibiotics.

Question 19. Which among the following are food additives?
(i) Food colours
(ii) Antioxidants
(iii) Stabilizers
(iv) Preservatives
(a) (i), (ii) & (iv)
(b) (i), (iii) & (iv)
(c) (i), (ii) & (iii)
(d) (i), (ii), (iii) & (iv)
Answer: (d) (i), (ii), (iii) & (iv)
In simple words: All the listed items – food colors, antioxidants, stabilizers, and preservatives – are types of food additives used to improve food.

🎯 Exam Tip: Food additives serve various purposes, including enhancing appearance (colors), preventing spoilage (antioxidants, preservatives), and maintaining texture (stabilizers).

Question 20. The preservative used for the preparation of pickles is
(a) benzoic acid
(b) sorbic acid
(c) acetic acid
(d) hydroxybenzoic acid
Answer: (c) acetic acid
In simple words: Acetic acid, which is found in vinegar, is commonly used to preserve pickles.

🎯 Exam Tip: Acetic acid is a widely recognized food preservative, especially in pickled products, due to its ability to inhibit microbial growth.

Question 21. Which of the following not correctly matched
(a) Neoprene - \( \text{+CH}_2\text{-C=CH-CH}_2\text{)}_n \) (where C has a Cl branch)
(b) Nylon - \( \text{+NH-(CH}_2\text{)}_6\text{-NHCO-(CH}_2\text{)}_4\text{-C)_n} \) (where C has double bond to O)
(c) Terylene - \( \text{+OCH}_2\text{-CH}_2\text{-O-C} \) (benzene ring) \( \text{C)_n} \) (where C has double bond to O)
(d) Poly acrylonitrile - \( \text{+CH}_2\text{-CH)_n} \) (where CH has a CN branch)
Answer: (d) Poly acrylonitrile - \( \text{+CH}_2\text{-CH)_n} \) (where CH has a CN branch)
In simple words: The structure shown for polyacrylonitrile is incorrect; the actual structure involves a repeating unit of \( \text{CH}_2\text{-CH(CN)} \). The provided structure in option (d) is not the correct representation for polyacrylonitrile.

🎯 Exam Tip: For polymer matching questions, accurately recall the monomer units and their polymerization to form the repeating unit of the polymer.

Question 22. Which among the following is used as an emulsifier?
(a) Sodium metabisulphite
(b) Alkyl ester of hydroxybenzoic acid
(c) Sucrose ester with palmitic acid
(d) All of the options
Answer: (c) Sucrose ester with palmitic acid
In simple words: Sucrose ester with palmitic acid is used as an emulsifier, which helps mix things like oil and water that normally do not mix well.

🎯 Exam Tip: Emulsifiers help stabilize mixtures of two immiscible liquids; sucrose esters of fatty acids are common examples in food products.

Question 23. Antioxidants are
(a) butyl hydroxy toluene
(b) butylated hydroxy anisole
(c) both (a) & (b)
(d) none of the options
Answer: (c) both (a) & (b)
In simple words: Both butyl hydroxy toluene (BHT) and butylated hydroxy anisole (BHA) are types of chemicals that prevent food from going bad quickly.

🎯 Exam Tip: Recognize common antioxidant food additives like BHT (butylated hydroxytoluene) and BHA (butylated hydroxyanisole).

Question 24. Sulphur dioxide acts as
(a) antimicrobial agent
(b) antioxidant
(c) enzyme inhibitor
(d) all of the options
Answer: (d) all of the options
In simple words: Sulfur dioxide works in many ways: it kills tiny harmful living things, stops fats from spoiling, and can block enzymes from working.

🎯 Exam Tip: Sulfur dioxide has multiple roles as a food additive, including antimicrobial, antioxidant, and enzyme inhibiting properties, making it versatile in food preservation.

Question 25. Artificial sweetening agent is
(a) Butyl hydroxytoluene
(b) Butylated hydroxyanisole
(c) alitame
(d) all of the options
Answer: (c) alitame
In simple words: Alitame is an artificial sweetener, used to make food taste sweet without adding sugar.

🎯 Exam Tip: Common artificial sweeteners include saccharin, aspartame, sucralose, and alitame.

Question 26. An example of anionic detergent is
(a) Sodium palmitate
(b) Potassium palmitate
(c) Sodium methylbenzene sulphonate
(d) Methyl hydrogen sulphate
Answer: (b) Potassium palmitate
In simple words: Potassium palmitate is a type of anionic detergent. These detergents have a negative charge on their cleaning part.

🎯 Exam Tip: Remember the basic structure of anionic detergents: they are sodium salts of sulphonated long-chain alcohols or hydrocarbons, identifiable by their negative charge.

Question 27. For a good soap, its TFM value should be
(a) higher
(b) lower
(c) minimum
(d) zero
Answer: (a) higher
In simple words: For soap to be considered good quality, its TFM (Total Fatty Matter) number should be high. A higher TFM means the soap has more pure cleaning ingredients.

🎯 Exam Tip: A higher TFM value indicates better soap quality, as it represents a greater proportion of fatty acids, which are the primary cleaning agents.

Question 28. As per BIS standards, grade -1 soaps should have a minimum TFM of
(a) 60%
(b) 70%
(c) 76%
(d) 50
Answer: (c) 76%
In simple words: To be called a Grade-1 soap by Indian standards, it must have at least 76% TFM, showing it has good cleaning power. This ensures a certain level of purity and effectiveness for consumers.

🎯 Exam Tip: Knowing specific regulatory standards like BIS TFM percentages helps in MCQs related to product quality and composition.

Question 29. An example of anionic detergent is
(a) Pentaerythrityl stearate
(b) Sodium lauryl sulphate
(c) Sodium stearate
(d) Sodium methylbenzene sulphonate
Answer: (b) Sodium lauryl sulphate
In simple words: Sodium lauryl sulphate is a common example of an anionic detergent, meaning its cleaning part carries a negative charge. It is widely used in many cleaning products.

🎯 Exam Tip: Anionic detergents are characterized by the anionic (negatively charged) part of the molecule being responsible for the cleansing action. Look for sulphate or sulphonate groups.

Question 30. Which among the following is a natural polymer?
(a) Cellulose diacetate
(b) Cellulose
(c) Polythene
(d) Viscose rayon
Answer: (b) Cellulose
In simple words: Cellulose comes from plants naturally, making it a natural polymer. It is a main part of plant cell walls.

🎯 Exam Tip: Natural polymers are found in nature, like cellulose in plants or proteins in animals, while synthetic polymers are man-made.

Question 31. Which among the following is a synthetic polymer?
(a) Cellulose diacetate
(b) Cellulose
(c) Polythene
(d) Viscose rayon
Answer: (c) Polythene
In simple words: Polythene is a man-made plastic, which makes it a synthetic polymer. It is used to make bags and containers.

🎯 Exam Tip: Synthetic polymers are human-made, often through polymerization processes, and are distinct from natural polymers which occur in living organisms.

Question 32. Which among the following is a semi-synthetic polymer?
(a) Cellulose diacetate
(b) Cellulose
(c) Polythene
(d) Polyvinyl chloride
Answer: (a) Cellulose diacetate
In simple words: Cellulose diacetate is a semi-synthetic polymer because it starts with natural cellulose and is then changed by humans. This makes it partly natural and partly man-made.

🎯 Exam Tip: Semi-synthetic polymers are derived from natural polymers through chemical modifications, combining natural origins with synthetic alterations.

Question 33. Which among the following is a linear polymer?
(a) LDPE
(b) HDPE
(c) Polypropylene
(d) Bakelite
Answer: (b) HDPE
In simple words: HDPE has long, straight chains of polymer molecules, making it a linear polymer. This structure gives it high density and strength.

🎯 Exam Tip: Linear polymers have monomer units linked to form long, straight chains, which pack closely, leading to high density and strength.

Question 34. Which among the following is a branched polymer?
(a) LDPE
(b) HOPE
(c) PVC
(d) Bakelite
Answer: (a) LDPE
In simple words: LDPE has chains with side branches, making it a branched polymer. This structure prevents close packing, giving it lower density and more flexibility.

🎯 Exam Tip: Branched polymers have side chains attached to the main polymer backbone, which reduces their packing efficiency and crystallinity.

Question 35. Which among the following is a cross-linked polymer?
(a) LDPE
(b) HDPE
(c) PVC
(d) Bakelite
Answer: (d) Bakelite
In simple words: Bakelite has a network structure where polymer chains are joined together by strong bonds, making it a cross-linked polymer. This makes it very hard and resistant to heat.

🎯 Exam Tip: Cross-linked polymers are characterized by a three-dimensional network structure formed by strong covalent bonds between polymer chains, leading to rigid and infusible materials.

Question 36. Which among the following is an elastomer?
(a) Nylon 6,6
(b) Polythene
(c) Neoprene
(d) Polystyrene
Answer: (c) Neoprene
In simple words: Neoprene is a type of rubber that can stretch a lot and then return to its original shape, so it is called an elastomer. It is very flexible and durable.

🎯 Exam Tip: Elastomers are polymers with rubber-like elasticity, capable of being stretched to many times their original length and recovering their shape after the stress is removed.

Question 37. Which among the following polymer belongs to fibers?
(a) Nylon 6,6
(b) Polythene
(c) Neoprene
(d) Polystyrene
Answer: (a) Nylon 6,6
In simple words: Nylon 6,6 is used to make strong threads and fabrics, so it belongs to the fiber category of polymers. Its strong intermolecular forces allow it to form long, thin strands.

🎯 Exam Tip: Fibers are polymers with strong intermolecular forces (like hydrogen bonding), leading to high tensile strength and used in textile applications.

Question 38. Which among the following is a thermoplastic?
(a) Nylon 6,6
(b) Polythene
(c) Neoprene
(d) Buna-N
Answer: (b) Polythene
In simple words: Polythene is a thermoplastic, which means it can be melted and reshaped many times. This makes it easy to recycle and use again.

🎯 Exam Tip: Thermoplastics are polymers that soften upon heating and harden upon cooling, a process that can be repeated, allowing them to be remolded.

Question 39. Which among the following is a thermosetting plastic?
(a) Nylon 6,6
(b) Polythene
(c) Neoprene
(d) Bakelite
Answer: (d) Bakelite
In simple words: Bakelite is a thermosetting plastic, meaning once it's heated and molded into a shape, it cannot be melted and reshaped again. This makes it very rigid and heat-resistant.

🎯 Exam Tip: Thermosetting plastics undergo irreversible chemical changes when heated, forming a permanent, rigid structure that cannot be softened or remolded.

Question 40. Which among the following is a condensation polymer?
(a) PVC
(b) Nylon 6,6
(c) Polythene
(d) Teflon
Answer: (b) Nylon 6,6
In simple words: Nylon 6,6 is a condensation polymer because it forms when two different molecules join, releasing a small molecule like water. This process builds a long chain.

🎯 Exam Tip: Condensation polymerization involves the loss of small molecules (like water or methanol) during the polymerization process, unlike addition polymerization where monomers simply add to each other.

Question 41. Which is used as a free radical initiator?
(a) Benzyl acetate
(b) Benzyl alcohol
(c) Benzoyl peroxide
(d) Benzyl nitrate
Answer: (c) Benzoyl peroxide
In simple words: Benzoyl peroxide starts reactions by creating free radicals, which are atoms with unpaired electrons. These radicals then help other molecules join together to form polymers.

🎯 Exam Tip: Free radical initiators are crucial in addition polymerization reactions, creating the initial radical species that propagate the chain growth.

Question 42. The catalyst used in the preparation of LDPE is
(a) Hydrogen
(b) Oxygen
(c) Zeigler-Natta catalyst
(d) Wilkinson catalyst
Answer: (b) Oxygen
In simple words: Oxygen acts as a catalyst for making LDPE, helping the process happen but not being used up itself. It helps the small molecules link up to form the polymer.

🎯 Exam Tip: Remember that LDPE (Low-Density Polyethylene) production typically uses free radical polymerization with oxygen as an initiator under high pressure and temperature.

Question 43. The catalyst used in the preparation of HDPE is
(a) Hydrogen
(b) Oxygen
(c) Zeigler-Natta catalyst
(d) Wilkinson catalyst
Answer: (c) Zeiglar-Natta catalyst
In simple words: The Zeigler-Natta catalyst is special for making HDPE, helping to create straight, tightly packed polymer chains. This results in a strong and dense plastic.

🎯 Exam Tip: HDPE (High-Density Polyethylene) is synthesized using Ziegler-Natta catalysts, which enable stereospecific polymerization and produce highly linear polymer chains.

Question 44. Zeiglar-Natta catalyst is
(a) \( \text{ZnCl}_2+(\text{C}_2\text{H}_5)_3\text{Al} \)
(b) \( \text{TiCl}_4+(\text{C}_2\text{H}_5)_3\text{Al} \)
(c) \( \text{AlCl}_3+(\text{C}_{25})_3\text{Al} \)
(d) \( \text{CuCl}_2+(\text{C}_2\text{H}_5)_3\text{Al} \)
Answer: (b) \( \text{TiCl}_4+(\text{C}_2\text{H}_5)_3\text{Al} \)
In simple words: A Zeigler-Natta catalyst is usually a mix of titanium tetrachloride and an alkyl aluminium compound. This special combination helps make polymers like HDPE with specific structures.

🎯 Exam Tip: Recognize the common components of a Ziegler-Natta catalyst: a transition metal halide (like \( \text{TiCl}_4 \)) and an organoaluminium compound (like \( (\text{C}_2\text{H}_5)_3\text{Al} \)).

Question 45. The monomer used in the manufacture of Teflon is
(a) Tetra fluoro methane
(b) Tetra chloromethane
(c) Tetra fluoro ethylene
(d) Tetra chloroethylene
Answer: (c) Tetra fluoro ethylene
In simple words: Teflon is made from small units called tetrafluoroethylene, which link together to form a long chain. This monomer is what gives Teflon its non-stick properties.

🎯 Exam Tip: The monomer name often gives a clue about the polymer name (e.g., tetrafluoroethylene for Teflon or PTFE, ethene for polythene).

Question 46. The chemical name of orlon is
(a) Polyethylene terephthalate
(b) Polyacrylonitrile
(c) Poly hexamethylene adipamide
(d) Poly tetrafluoroethylene
Answer: (b) Polyacrylonitrile
In simple words: Orlon is chemically known as polyacrylonitrile, a polymer made from many acrylonitrile units joined together. It is a synthetic fiber used in textiles.

🎯 Exam Tip: Memorize the common names and chemical names of important polymers, especially those used as fibers or plastics.

Question 47. The monomer of nylon 6 is
(a) Hexan-1,6-dioic acid
(b) Hexan-1, 6-diamine
(c) Caprolactam
(d) Both (a) & (b)
Answer: (c) Caprolactam
In simple words: Nylon 6 is made from a single type of molecule called caprolactam. This molecule opens up and links to other similar molecules to form the polymer chain.

🎯 Exam Tip: Nylon 6 is unique because it's formed from a single cyclic monomer (caprolactam) through ring-opening polymerization, unlike Nylon 6,6 which uses two different monomers.

Question 48. The monomer of nylon 6,6 is
(a) Hexan-1,6-dioic acid
(b) Hexan-1, 6-diamine
(c) Caprolactam
(d) Both (a) & (b)
Answer: (d) Both (a) & (b)
In simple words: Nylon 6,6 is created by joining two different molecules: hexan-1,6-dioic acid and hexan-1,6-diamine. These two parts combine to form the strong polymer.

🎯 Exam Tip: The "6,6" in Nylon 6,6 indicates that both monomers (hexamethylenediamine and adipic acid) contain six carbon atoms each.

Question 49. Terylene is an example of
(a) Poly amide
(b) Polyester
(c) Polyene
(d) Poly acid
Answer: (b) Polyester
In simple words: Terylene is a type of polyester, which means it's a polymer whose units are linked by ester bonds. It is commonly used to make fabrics.

🎯 Exam Tip: Polyesters are formed by the condensation reaction between a diol and a dicarboxylic acid or a diester. Terylene (Dacron) is a classic example.

Question 50. The polymer used to make unbreakable crockery is
(a) Novolac
(b) Bakelite
(c) Melamine formaldehyde
(d) Urea formaldehyde
Answer: (c) Melamine formaldehyde
In simple words: Melamine formaldehyde is a polymer known for making strong, unbreakable dishes. It's a hard plastic that resists heat and breaking.

🎯 Exam Tip: Recognize that melamine formaldehyde resin is a thermosetting polymer valued for its hardness, scratch resistance, and heat stability, making it ideal for dinnerware.

Question 51. Natural rubber is a polymer of
(a) Chloroprene
(b) 2-methyl buta-1,3-diene
(c) 2-chloro buta-1, 3-diene
(d) Acrylonitrile
Answer: (b) 2-methyl buta-1, 3-diene
In simple words: Natural rubber is made up of many repeating units of 2-methyl buta-1,3-diene, also known as isoprene. These units link together to form the stretchy rubber material.

🎯 Exam Tip: Isoprene (2-methyl buta-1,3-diene) is the fundamental monomer of natural rubber, and its cis-configuration is responsible for the elasticity.

Question 52. Which is used in vulcanization of rubber?
(a) Carbon
(b) Nitrogen
(c) Sulphur
(d) Chlorine
Answer: (c) Sulphur
In simple words: Sulphur is added to rubber and heated in a process called vulcanization to make the rubber stronger and more durable. It creates cross-links between the rubber chains.

🎯 Exam Tip: Vulcanization is a key process for improving rubber's properties by forming sulfur cross-links, enhancing its strength, elasticity, and resistance to temperature changes.

Question 53. The polymer used in the manufacture of conveyer belts is
(a) Buna – N
(b) Buna - S
(c) Neoprene
(d) Chloroprene
Answer: (c) Neoprene
In simple words: Neoprene, a synthetic rubber, is strong and resistant to oil and heat, making it suitable for manufacturing conveyor belts. Its durability helps belts last longer.

🎯 Exam Tip: Neoprene (polychloroprene) is known for its excellent resistance to oil, chemicals, and weathering, making it suitable for applications like conveyor belts and hoses.

Question 54. Which among the following is not a copolymer?
(a) Neoprene
(b) Buna – N
(c) Buna – S
(d) All of the options
Answer: (a) Neoprene
In simple words: Neoprene is made from only one type of monomer, chloroprene, so it's not a copolymer. Copolymers are made from two or more different monomers.

🎯 Exam Tip: A homopolymer is formed from a single type of monomer, whereas a copolymer is formed from two or more different types of monomers.

Question 55. Which among the following is a biodegradable polymer?
(a) PCA
(b) Nylon-6
(c) PVC
(d) HDPE
Answer: (a) PGA
In simple words: PGA (Polyglycolic acid) is a biodegradable polymer, meaning it can break down naturally over time. This makes it useful for things like medical stitches that dissolve in the body.

🎯 Exam Tip: Biodegradable polymers are environmentally friendly as they decompose into natural substances by microbial action, unlike many synthetic plastics.

II. Pick Out the Correct Statements

Question 1.
(i) All drugs belonging to penicillin group have same biological action.
(ii) The drug molecule interacts with biomolecules such as enzymes, receptors etc., which are referred as drug targets.
(iii) In all living systems, the biochemical reactions are catalysed by hormones.
(iv) The substrate molecule binds to the active site of the enzymes by means of strong covalent bonding.
(a) (i) & (ii)
(b) (ii) & (iii)
(c) (iii) & (iv)
(d) (i) & (iv)
Answer: (a) (i) & (ii)
In simple words: Statements (i) and (ii) are correct. All penicillin drugs work similarly, and drugs usually target specific molecules in the body to have an effect.

🎯 Exam Tip: When identifying correct statements, evaluate each one individually based on your knowledge of pharmacology and biochemistry. Hormones regulate, but enzymes catalyze; substrate binding is often non-covalent.

Question 2. A drug is safer when its therapeutic index is
(i) Many drugs exert their physiological effects by binding to a specific molecule called a receptor.
(ii) Receptors bind to the active site of messengers.
(iii) Compounds that carry messages to cells are called chemical messengers.
(iv) Most receptors are chiral and hence different enantiomers of a drug can have different effect.
(a) (i) & (ii)
(b) (ii) & (iii)
(c) (iii) & (iv)
(d) (i) & (iv)
Answer: (c) (iii) & (iv)
In simple words: Statements (iii) and (iv) are correct. Chemical messengers send signals in cells, and because most receptors have a specific shape (chiral), different forms of a drug can act differently.

🎯 Exam Tip: Focus on fundamental biological principles: chemical messengers are how cells communicate, and the chirality of receptors means that a drug's specific 3D shape greatly influences its effect.

Question 3.
(i) Aspirin prevents coagulation and hence useful in the prevention of heart attacks.
(ii) Lidocaine is used for major surgical procedures.
(iii) Procaine block pain perception that is transmitted via peripheral nerve fibres to the brain.
(iv) Fluoroquinolones increase the activity of bacterial enzyme DNA gyrase.
(a) (i) & (ii)
(b) (ii) & (iii)
(c) (i) & (iii)
(d) (i) & (iv)
Answer: (c) (i) & (iii)
In simple words: Statements (i) and (iii) are correct. Aspirin helps stop blood from clotting, which can prevent heart attacks. Procaine stops pain signals from reaching the brain.

🎯 Exam Tip: Carefully recall the specific actions of each drug class. Lidocaine is for minor procedures, and fluoroquinolones *inhibit* DNA gyrase, not increase its activity.

Question 4.
(i) In soap manufacture common salt is added to the reaction mixture to increase the solubility of soap which helps the precipitation of soap from the aqueous solution.
(ii) In soap the hydrocarbon portion is non-polar and the carboxyl portion is polar
(iii) In soap the hydrocarbon portion is water soluble and the carboxyl portion is soluble in oil or grease.
(iv) The cleansing ability of a soap depends upon its tendency to act as an emulsifying agent between water and water insoluble grease.
(a) (i) & (ii)
(b) (ii) & (iii)
(c) (ii) & (iv)
(d) (i) & (iv)
Answer: (c) (ii) & (iv)
In simple words: Statements (ii) and (iv) are correct. Soap has a fat-loving and a water-loving part, and it cleans by acting like a bridge between oil and water, pulling dirt away. Common salt is added to *decrease* soap solubility to help it separate.

🎯 Exam Tip: Understand the dual nature of soap molecules (hydrophobic hydrocarbon tail and hydrophilic carboxylate head) and their role as emulsifying agents. Salt decreases solubility, causing soap to "salt out".

III. Pick Out the Incorrect Statements

Question 1.
(i) Natural polymers are obtained from plants or animals.
(ii) Natural polymers modified by chemical treatment are called synthetic polymers.
(iii) Addition polymers are formed by the polymerisation of monomers without the elimination of any by product.
(iv) Thermosetting plastics can be remoulded,
(a) (i) & (ii)
(b) (ii) & (iii)
(c) (ii) & (iv)
(d) (i) & (iii)
Answer: (c) (ii) & (iv)
In simple words: Statements (ii) and (iv) are incorrect. Natural polymers changed chemically are called semi-synthetic, not synthetic. Also, thermosetting plastics cannot be melted and reshaped once hardened.

🎯 Exam Tip: Differentiate clearly between natural, semi-synthetic, and synthetic polymers. Also, remember that thermosetting plastics undergo irreversible curing and cannot be remolded, which is a key distinction from thermoplastics.

Question 2.
(i) Polyethene is obtained by condensation polymerisation.
(ii) In the preparation of HDPE peroxides formed from oxygen acts as a free radical initiator.
(iii) The monomer of teflon is tetrafluoroethylene.
(iv) Orlon is polyacrylonitrile.
(a) (i) & (ii)
(b) (ii) & (iii)
(c) (iii) & (iv)
(d) (i) & (iv)
Answer: (a) (i) & (ii)
In simple words: Statements (i) and (ii) are incorrect. Polyethene is made by addition polymerization, not condensation. For HDPE, a Ziegler-Natta catalyst is used, not peroxides as free radical initiators (which are for LDPE).

🎯 Exam Tip: Know the polymerization types for common polymers: Polythene (addition), Nylon (condensation). Also, distinguish between LDPE (free radical, oxygen initiator) and HDPE (Ziegler-Natta catalyst) synthesis.

Question 3.
(i) Proteins which act as biological catalysts are called enzymes.
(ii) Proteins which are important for communication systems are called receptors.
(iii) Allosteric inhibitors do not change the active site geometry of enzymes.
(iv) When allosteric inhibitors bind to the allosteric site, the substrate can also bind to the enzyme.
(a) (i) & (ii)
(b) (ii) & (iii)
(c) (iii) & (iv)
(d) (i) & (iv)
Answer: (c) (iii) & (iv)
In simple words: Statements (iii) and (iv) are incorrect. Allosteric inhibitors actually change an enzyme's shape, preventing a substrate from binding. Also, when these inhibitors are present, the original substrate often *cannot* bind to the enzyme.

🎯 Exam Tip: Allosteric inhibitors bind to a site other than the active site, causing a conformational change that alters the active site's shape and prevents substrate binding. This is a crucial concept in enzyme kinetics.

Question 4.
(i) For the treatment of stress, anxiety, depression tranquilizers are used.
(ii) Non-narcotic analgesics are mainly used for post operative pain, pain of terminal cancer.
(iii) In the treatment of peptic ulcer tetracyclines are used.
(iv) Rabeprazole is used as an antacid,
(a) (i) & (ii)
(b) (ii) & (iii)
(c) (iii) & (iv)
(d) (i) & (iv)
Answer: (b) (ii) & (iii)
In simple words: Statements (ii) and (iii) are incorrect. Non-narcotic pain relievers are for mild to moderate pain, not severe pain like cancer pain. Also, tetracyclines are antibiotics, not a primary treatment for peptic ulcers, which are often treated with antacids or proton pump inhibitors.

🎯 Exam Tip: Differentiate between drug classes and their primary uses: tranquilizers for mood disorders, non-narcotics for mild pain, narcotics for severe pain. Peptic ulcers are complex and treated with a combination of drugs, but tetracyclines are not generally first-line treatments.

IV. Assertion and Reason

Question. Assertion : The quality of soap is described in terms of total fatty matter (TFM value) Reason : As per BIS Standards, Grade-I soaps should have 60% minimum TFM value.
(a) If both assertion and reason are true and reason is correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false
(d) Both assertion and reason are false.
Answer: (c) Assertion is true but reason is false
In simple words: The quality of soap is measured by TFM, which is true. However, Grade-I soaps need a minimum of 76% TFM, not 60%. TFM helps consumers know how much actual soap is in the product, indicating its cleaning power. So the reason is false.

🎯 Exam Tip: Remember the specific TFM percentages for different grades of soap to avoid common traps in assertion-reason questions.

Question. Assertion : Paracetamol and aspirin are both antipyretics. Reason: Both paracetamol and aspirin are controlled and reversible loss of concionsness by affecting central nervous system.
(a) Both assertion and reason are true and reason is correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation for assertion,
(c) Assertion is true but reason is false
(d) Both assertion and reason are false.
Answer: (c) Assertion is true but reason is false
In simple words: Paracetamol and aspirin are indeed used to reduce fever, so the assertion is true. However, their main function is not to cause controlled loss of consciousness by affecting the central nervous system, so the reason is false. Antipyretics help bring down high body temperature, making a person feel more comfortable.

🎯 Exam Tip: Clearly distinguish between a drug's primary function and its side effects or alternative actions when evaluating assertion-reason statements.

Question 3. Assertion (A): Soaps are superior to detergents. Reason (R): Detergents can be used even in hard water,
(a) Both (A) and (R) are correct, (R) explains (A)
(b) Both (A) and (R) are correct, but (R) does not explain (A)
(c) (A) is correct but (R) is wrong
(d) (A) is wrong but (R) is correct
Answer: (d) (A) is wrong but (R) is correct
In simple words: Soaps are actually not better than detergents, so the assertion is false. However, it is true that detergents work well even with hard water. Detergents are more effective in hard water because they do not form scum with minerals like soaps do.

🎯 Exam Tip: Remember that detergents are generally more versatile than soaps, especially in hard water conditions, due to their chemical structure.

Question 4. Assertion (A): Nylon 6,6 is a condensation polymer. Reason (R): Addition polymers are formed by the polymerisation of monomers without the elimination of any product.
(a) Both (A) and (R) are correct, (R) explains (A)
(b) Both (A) and (R) are correct, but (R) does not explain (A)
(c) (A) is correct but (R) is wrong
Answer: (b) Both (A) and (R) are correct, but (R) does not explain (A)
In simple words: Nylon 6,6 is indeed made by condensation, which is true. It is also true that addition polymers form without losing any small molecules. However, the reason about addition polymers does not explain why nylon 6,6 is a condensation polymer. Condensation polymerization often involves the removal of small molecules like water or HCl, unlike addition polymerization where monomers simply join together.

🎯 Exam Tip: Always check if the reason directly explains the assertion, even if both statements are individually true. The relationship between them is crucial.

V. Match the Following

Question 1. Match the anaesthetics with their examples.
1. Ester-linked local anaesthetic
2. Amide-linked local anaesthetic
3. Intravenous general anaesthetic
4. Inhalational general anaesthetic
a. Propofol
b. Isoflurane
c. Lidocaine
d. Procaine
Answer:
1. - d. Procaine
2. - c. Lidocaine
3. - a. Propofol
4. - b. Isoflurane
In simple words: This table shows how different types of anaesthetic medicines are matched with their specific examples. Anaesthetics help stop pain or make someone sleep for a medical procedure. Anaesthetics are crucial in medicine, allowing patients to undergo surgeries and painful treatments without discomfort.

🎯 Exam Tip: Memorize the classifications of anaesthetics and their corresponding examples, as this is a common matching question type.

Question 2. Match the drugs with their examples.
1. Tranquilizer
2. Non-narcotic analgesic
3. Opioid
4. Antihistamine
5. Antimicrobial
6. Antiseptic
7. Antifertility drug
a. Erythromycin
b. Menstranol
c. Benzalkonium chloride
d. Alprazolam
e. Cetirizine
f. Ibuprofen
g. Codeine
Answer:
1. - d. Alprazolam
2. - f. Ibuprofen
3. - g. Codeine
4. - e. Cetirizine
5. - a. Erythromycin
6. - c. Benzalkonium chloride
7. - b. Menstranol
In simple words: This table matches different kinds of medicines with specific examples. It shows which medicine belongs to which group, like Alprazolam for tranquilizers or Ibuprofen for pain relief. Each type of drug has a special job in the body, helping to treat different conditions or symptoms.

🎯 Exam Tip: Focus on understanding the primary action of each drug class to correctly identify its examples in matching exercises.

Question 3. Match the monomers with their polymers.
1. Butadiene & styrene
2. 3-hydroxybutanoic acid & 3-hydroxypentanoic acid
3. Vinyl Chloride
4. Butadiene & Acrylonitrile
5. Phenol & formaldehyde
a. Bakelite
b. Buna-N
c. Buna-S
d. PHBV
e. PVC
Answer:
1. - c. Buna-S
2. - d. PHBV
3. - e. PVC
4. - b. Buna-N
5. - a. Bakelite
In simple words: This table shows how small units called monomers join together to create larger materials called polymers. Each polymer is made from its own specific monomer building blocks. Understanding which monomers form which polymers is key to creating many useful materials, from plastics to synthetic rubbers.

🎯 Exam Tip: Pay close attention to the specific monomer components for each polymer, as many polymer names are derived from their monomers.

VI. Two Mark Questions

Question 1. What is called as medicine?
Answer: A medicine is a drug that works with large molecules like proteins in the body to create a helpful health effect. It aims to improve health and treat illness. Medicines are designed to target specific biological pathways to restore normal body function or fight infections.
In simple words: Medicine is a substance that interacts with parts of our body, like proteins, to help us feel better or cure diseases.

🎯 Exam Tip: When defining medicine, emphasize its interaction with biological targets and its therapeutic purpose.

Question 2. What are the characteristics of an ideal drug?
Answer: An ideal drug should have several good qualities. It should not be poisonous and should work well with the body (bio-compatible). It should also break down naturally in the body (biodegradable) and not cause any bad side effects. The goal in drug development is to create medicines that are highly effective while having minimal adverse effects on the patient.
In simple words: A perfect drug should not be toxic, work well with the body, break down easily, and have no side effects.

🎯 Exam Tip: List the key ideal characteristics clearly, focusing on safety, effectiveness, and environmental considerations.

Question 3. What is therapeutic index? How is it related to the safety of the drug?
Answer: The therapeutic index measures how safe a drug is. It is found by dividing the highest dose a body can handle without becoming toxic (maximum tolerated dose) by the lowest dose needed to start curing a problem (minimum curative dose). A higher therapeutic index means the drug is safer to use. This indicates a wider margin between effective and harmful doses. A high therapeutic index allows doctors to prescribe a wide range of doses, increasing flexibility and safety for patients.
In simple words: The therapeutic index tells us how safe a medicine is. A bigger number means the medicine is safer, as there's a wider gap between a dose that helps and a dose that harms.

🎯 Exam Tip: Clearly state the definition as a ratio and explain the direct relationship between a higher index and greater drug safety.

Question 4. What are competitive inhibitors?
Answer: Competitive inhibitors are drug molecules that look very similar to the natural substances (substrates) an enzyme usually acts on. When these drugs are given, they can attach to the enzyme's active spot, stopping the enzyme from doing its normal job. In simple terms, they compete with the natural substrate to block the enzyme's activity. This type of inhibition is reversible; increasing the concentration of the natural substrate can overcome the effects of a competitive inhibitor.
In simple words: Competitive inhibitors are like fake keys that fit into an enzyme's lock, blocking the real key (substrate) and stopping the enzyme from working.

🎯 Exam Tip: Highlight that competitive inhibitors mimic the substrate and bind to the active site, and that their effect can be overcome by increasing substrate concentration.

Question 5. What are antacids? Explain their mode of action and uses. Give examples.
Answer: Antacids are substances that help to neutralize the extra acid in the stomach, which causes problems like heartburn and acidity. They work by reacting with the stomach acid to make it less acidic. This helps to ease the burning feeling in the chest or throat caused by acid reflux. Common examples include Milk of Magnesia and Aluminium hydroxide. Antacids provide quick relief for occasional indigestion, but they do not treat the underlying cause of chronic acid issues.
In simple words: Antacids calm upset stomachs by making stomach acid less strong. They help with heartburn and use things like Milk of Magnesia.

🎯 Exam Tip: Mention both the neutralizing action and the relief of symptoms, along with common examples to score full marks.

Question 6. What are antihistamines? Give an example.
Answer: Antihistamines are medicines that stop the body from releasing histamine, which is a chemical released during allergic reactions. They work by blocking certain receptors (histamine-1 receptors) where histamine normally binds. This helps to reduce allergy symptoms like itching, sneezing, and runny nose. Histamine plays a key role in the immune response, and blocking it can prevent or alleviate many common allergy symptoms.
In simple words: Antihistamines stop the body from reacting to allergens by blocking histamine, a chemical that causes allergy symptoms.

🎯 Exam Tip: Define their function clearly and provide a general type of drug, such as H1-receptor antagonists, as an example.

Question 7. What are food additives?
Answer: Food additives are special substances that are not naturally found in food but are added to it. They are used to make the food better, for example, to improve its taste, look, freshness, or how long it lasts. These additives are carefully regulated to ensure they are safe for consumption and serve a useful purpose in food production.
In simple words: Food additives are things added to food that aren't usually in it, to make it taste better, look better, or stay fresh longer.

🎯 Exam Tip: Emphasize that food additives are non-natural components added to enhance specific food characteristics.

Question 8. Write the important categories of food additives.
Answer: Important categories of food additives include aroma compounds, which improve smell; preservatives, which keep food from spoiling; artificial sweeteners, which add sweetness without extra sugar; buffering substances, which control acidity; and vitamins and minerals, which add nutrients. Each category of additive serves a distinct purpose in food processing, contributing to the product's overall quality and shelf-life.
In simple words: Food additives come in groups like aroma compounds, preservatives, artificial sweeteners, buffering substances, and vitamins and minerals.

🎯 Exam Tip: List at least three distinct categories with a brief explanation of each to demonstrate comprehensive knowledge.

Question 9. What are the advantages of food additives?
Answer: Food additives offer several benefits: preservatives make food last longer by preventing spoilage; vitamins and minerals can add important nutrients; flavouring agents make food smell and taste better; and antioxidants stop fats and other food parts from reacting with air to form harmful substances. These benefits ensure that food remains safe, appealing, and nutritious for consumers over a longer period.
In simple words: Food additives help food last longer, add nutrients, improve taste and smell, and stop harmful chemicals from forming.

🎯 Exam Tip: Focus on the practical benefits of additives, such as extending shelf-life, enhancing sensory qualities, and nutritional value.

Question 10. What are sugar substituents? Give examples.
Answer: Sugar substitutes are special compounds that taste sweet like sugar but are processed by the body differently, often without needing insulin. This makes them useful for people who need to manage their blood sugar. Examples include Sorbitol, Xylitol, and Mannitol. These alternatives are commonly found in "sugar-free" products, helping to reduce calorie intake and manage diabetes.
In simple words: Sugar substitutes taste sweet but don't affect blood sugar levels like regular sugar, and examples are Sorbitol and Xylitol.

🎯 Exam Tip: Emphasize their sweetening property and their metabolic difference from regular sugar, noting their importance for diabetics.

Question 11. What are artificial sweetening agents? Give examples.
Answer: Artificial sweetening agents are man-made substances that taste very sweet but provide little to no calories or nutrients. They are used to sweeten foods and drinks without adding sugar. Examples include Saccharin, Aspartame, Sucralose, and Alitame. These sweeteners are much sweeter than natural sugar, so only a tiny amount is needed to achieve the desired sweetness.
In simple words: Artificial sweeteners are man-made substances that make things taste sweet without adding sugar or calories. Saccharin and Aspartame are examples.

🎯 Exam Tip: Distinguish artificial sweeteners by their synthetic nature, intense sweetness, and negligible nutritional value, along with common examples.

Question 12. Define soap and detergent.
Answer: Soap is a cleaning agent made from the sodium or potassium salts of long-chain fatty acids. Detergent, on the other hand, is a cleaning agent made from the sodium salts of alkyl hydrogen sulphates or alkyl benzene sulphonic acids. Detergents generally perform better in hard water. The chemical structure of detergents allows them to prevent the formation of scum in hard water, unlike traditional soaps.
In simple words: Soap is a salt made from fatty acids, while detergent is a salt made from different chemical acids, both used for cleaning.

🎯 Exam Tip: Clearly state the chemical composition for both soap (fatty acid salts) and detergent (sulfonate salts) and mention their main difference in hard water.

Question 13. How is Teflon prepared? Mention its use.
Answer: Teflon is prepared through addition polymerization. The monomer used is tetrafluoroethylene, and the reaction is started with a catalyst like oxygen or ammonium persulphate, often under high pressure. The final product is Teflon, a polymer known for its non-stick properties. It is mainly used as a coating for non-stick cooking pans and other utensils. Teflon's unique chemical inertness and low friction make it valuable not just in cookware but also in industrial applications and medical implants.
\[ n \, CF_2=CF_2 \quad \xrightarrow{\text{High Pressure, Catalyst}} \quad \begin{pmatrix} CF_2 - CF_2 \end{pmatrix}_n \]
In simple words: Teflon is made by joining many small tetrafluoroethylene units together. It's used to make pans non-stick because of its special slippery surface.

🎯 Exam Tip: Remember the specific monomer (tetrafluoroethylene) and the polymerization type (addition) for Teflon, along with its primary non-stick application.

Question 14. How is Orlon prepared? Mention its use.
Answer: Orlon, also known as polyacrylonitrile, is prepared through an addition polymerization reaction. The monomer used is vinyl cyanide, also called acrylonitrile. This process is initiated by a peroxide catalyst. Orlon is widely used as a substitute for wool in making blankets, sweaters, and other textile products. Orlon is popular because it is lightweight, warm, and durable, making it an excellent synthetic alternative to natural wool.
In simple words: Orlon is made by joining many acrylonitrile units using a peroxide catalyst. It is used as a wool-like material for clothes and blankets.

🎯 Exam Tip: Identify acrylonitrile as the monomer and addition polymerization as the method, along with its use as a wool substitute.

Question 15. Differentiate addition polymerization and condensation polymerization.
Answer:

🎯 Exam Tip: When differentiating, clearly state the presence/absence of byproduct elimination, the type of growth (chain/step), and the monomer characteristics for each.

Question 16. What are antiseptics? Give an example.
Answer: Antiseptics are special chemicals that either stop or slow down the growth of tiny living things called microorganisms. They are safe enough to be used on living body tissues, such as skin. Good examples include hydrogen peroxide, povidone-iodine, and benzalkonium chloride. Antiseptics are essential for preventing infections in cuts, wounds, and during surgical procedures.
In simple words: Antiseptics are chemicals that slow or stop germ growth on living skin. Hydrogen peroxide is an example.

🎯 Exam Tip: Define antiseptics by their function (inhibit microbial growth) and application (living tissues), providing a common example.

VII. Three Mark Questions

Question 1. Write notes on antagonists and agonists.
Answer: Many medicines work by attaching to special molecules called receptors in the body. **Antagonists** are drugs that attach to a receptor and stop its normal function. They block what the natural chemical messenger would usually do. For example, caffeine is an antagonist that blocks adenosine receptors, making us feel less sleepy. **Agonists** are drugs that act like the body's natural messengers. They attach to receptors and turn them on, causing the same effects as the natural chemical. For instance, morphine is an agonist that binds to opioid receptors, helping to relieve pain. This precise interaction with receptors allows drugs to selectively target and modify specific biological processes in the body.
In simple words: Antagonists block signals at receptors, while agonists copy natural signals to turn receptors on. They both change how our body works.

🎯 Exam Tip: Clearly define each term, explain its mechanism of action (blocking vs. mimicking), and provide a distinct example for both antagonists and agonists.

Question 2. Write about antioxidants.
Answer: Antioxidants are substances that slow down the spoilage of food caused by oxidation, especially in foods with fats and oils. Fats and oils can easily react with oxygen and go bad, becoming rancid. To stop this from happening, antioxidants like BHT (butylhydroxytoluene) and BHA (butylated hydroxyanisole) are added to foods as preservatives. These additives work by reacting with harmful free radicals that cause oxidation, thereby breaking the chain reaction that leads to spoilage. In addition to food preservation, antioxidants are also important in biology for protecting cells from damage by free radicals.
In simple words: Antioxidants are chemicals that stop food, especially oily food, from going bad too quickly. They do this by stopping harmful reactions with oxygen.

🎯 Exam Tip: Explain how antioxidants prevent oxidative deterioration, mention their specific use in food preservation, and provide chemical examples like BHT or BHA.

Question 3. Write about the preparation of soaps.
Answer: Soaps are made from animal fats or vegetable oils, which are essentially glyceryl esters of long-chain fatty acids. When these fats or oils are heated with strong bases like sodium hydroxide or potassium hydroxide, a chemical reaction called saponification occurs. This reaction produces soap (which is the sodium or potassium salt of fatty acids) and glycerol. To separate the soap from the watery solution, common salt is added, which makes the soap less soluble and causes it to precipitate out. Finally, the soap can be mixed with colors, scents, and other useful chemicals. Saponification is one of the oldest chemical reactions used by humans, dating back thousands of years.
In simple words: Soaps are made by boiling animal fats or plant oils with a strong chemical like sodium hydroxide. This process, called saponification, makes soap and glycerol, which are then separated.

🎯 Exam Tip: Describe saponification as the core reaction, identifying the reactants (fats/oils and alkali) and products (soap and glycerol), and briefly mention the salt addition for precipitation.

Question 4. Write a note on Total Fatty Matter (TFM) of soap
Answer: Total Fatty Matter (TFM) is a key measure used to describe the quality of a soap. It tells you the total amount of fat, or fatty matter, that can be separated from a soap sample after using strong acids. A higher TFM value means the soap is of better quality, often indicating better cleaning and lathering properties. According to BIS (Bureau of Indian Standards) rules, Grade-1 soaps must have a minimum TFM value of 76%, while Grade-2 soaps require at least 70%. TFM is an important quality control parameter for soaps, directly influencing their cleaning efficiency and shelf stability.
In simple words: TFM shows how much real soap is in a bar; a higher number means better quality soap. Good soaps have a TFM of 76% or more.

🎯 Exam Tip: Define TFM as a measure of soap quality, explain its determination, and cite the minimum percentage requirements for different soap grades.

Question 6. How is nylon 6,6 prepared? Mention its use.
Answer: Nylon 6,6 is prepared through a condensation polymerization reaction. The process starts with two monomers in equal amounts: adipic acid and hexamethylenediamine. These react to form a nylon salt intermediate, which then undergoes heating to eliminate water molecules, forming polyhexamethylene adipamide, known as Nylon 6,6. This strong polymer is widely used in textiles and for manufacturing things like cards. Nylon 6,6 is a popular synthetic fiber known for its excellent strength, elasticity, and abrasion resistance, making it suitable for many industrial and consumer products.
\[ HOOC-(CH_2)_4-COOH \quad + \quad H_2N-(CH_2)_6-NH_2 \quad \xrightarrow{} \quad \text{Nylon salt} \]
\[ \text{Nylon salt} \quad \xrightarrow{\Delta} \quad \begin{pmatrix} -NH-(CH_2)_6-NH-CO-(CH_2)_4-CO- \end{pmatrix}_n \]
\[ \text{Poly (hexamethyleneadipamide) Nylon 6,6} \]
In simple words: Nylon 6,6 is made by joining two different chemical units (adipic acid and hexamethylenediamine) together, while also removing water. It is a strong material used for fabrics and other items.

🎯 Exam Tip: State the monomers (adipic acid and hexamethylenediamine) and polymerization type (condensation), and list key applications in textiles and durable goods.

Question 7. How is Nylon 6 prepared? Mention its use.
Answer: Nylon 6 is prepared by heating caprolactam, which is its monomer. When caprolactam is heated to 533K (260°C) in an inert atmosphere and with a tiny bit of water, it transforms into an amino caproic acid. This amino caproic acid then polymerizes to form Nylon 6. This polymer is used in manufacturing tire cords, fabrics, and ropes. The ring-opening polymerization of caprolactam is a key method for producing this versatile polymer.
\[ \text{Caprolactam (monomer)} \quad \xrightarrow{\text{533K, H}_2\text{O}} \quad H_2N-(CH_2)_5-COOH \]
\[ H_2N-(CH_2)_5-COOH \quad \xrightarrow{\text{-H}_2\text{O}} \quad \begin{pmatrix} -NH-(CH_2)_5-CO- \end{pmatrix}_n \]
\[ \text{Nylon 6 (polymer)} \]
In simple words: Nylon 6 is made by heating a chemical called caprolactam. This process creates a long chain that makes up Nylon 6. It's used for things like tire cords and other strong materials.

🎯 Exam Tip: Remember caprolactam as the sole monomer and mention its ring-opening polymerization, along with applications in strong fibers like tire cords.

Question 8. How is Bakelite prepared? Mention its uses.
Answer: Bakelite is prepared through a condensation polymerization reaction involving two monomers: phenol and formaldehyde. This reaction uses an acid or base as a catalyst. Initially, it forms an intermediate product like ortho- or para-hydroxymethylphenol. This intermediate then reacts with more phenol to create a linear polymer called Novolac. When Novolac is heated with formaldehyde, it forms cross-links, creating the hard, thermosetting polymer known as Bakelite. Novolac itself is used in paints. The softer forms of Bakelite are used for glues and varnishes, while hard Bakelite is used for items like combs and pens. Bakelite was the first synthetic plastic, revolutionizing manufacturing due to its durability, heat resistance, and electrical insulating properties.
\[ n \, \text{Phenol} \quad + \quad n \, \text{Formaldehyde} \quad \xrightarrow{H^+ \text{ or } OH^-} \quad \text{Novolac} \]
\[ \text{Novolac} \quad + \quad \text{Formaldehyde} \quad \xrightarrow{\text{heating}} \quad \text{Bakelite (cross-linked polymer)} \]
In simple words: Bakelite is made by joining phenol and formaldehyde chemicals. It first forms a straight chain polymer, then with more formaldehyde, it becomes a hard, cross-linked plastic. It is used for making strong items like combs and also for paints.

🎯 Exam Tip: Detail the two-step process (Novolac formation then cross-linking), identify phenol and formaldehyde as monomers, and list diverse uses for both linear and cross-linked forms.

Question 9. How is melamine formaldehyde prepared? Mention its use.
Answer: Melamine formaldehyde polymer is made through a process called condensation polymerization. The main ingredients, or monomers, are melamine and formaldehyde. When these two substances react, they join together to form the melamine formaldehyde polymer. This polymer is very useful for making strong, unbreakable items like crockery that can withstand daily use.
In simple words: Melamine formaldehyde is created by joining melamine and formaldehyde chemicals. It is used to make things like unbreakable plates and cups.

🎯 Exam Tip: Remember that condensation polymerization often involves the removal of a small molecule, like water, during the process of forming the polymer.

Question 10. How is urea formaldehyde polymer is prepared?
Answer: The urea formaldehyde polymer is created using condensation polymerization. This reaction involves two monomers: urea and formaldehyde. They react together, often with the removal of a water molecule, to form the long polymer chains. The resulting polymer is known as urea formaldehyde polymer and is commonly used in various products due to its properties.
In simple words: Urea formaldehyde polymer is made by combining urea and formaldehyde. It is formed when these two chemicals link up.

🎯 Exam Tip: When preparing for questions on polymer synthesis, always know the specific monomers, the type of polymerization (addition or condensation), and the main product formed.

Question 11. Differentiate natural rubber and synthetic rubber.
Answer:

🎯 Exam Tip: When differentiating, always focus on key characteristics like origin, monomer units, and physical properties for clear distinctions.

Question 12. Write about Neoprene preparation? Mention its use.
Answer: Neoprene is prepared through a process called free radical polymerization. Its monomer is 2-chloro buta-1, 3-diene, also known as chloroprene. This polymer is special because it is superior to natural rubber and can resist chemical reactions very well. Neoprene is often used to make chemical containers and conveyor belts because of its durability.
In simple words: Neoprene is made by linking together many chloroprene units. It is stronger than natural rubber and resists chemicals, so it's used for things like chemical containers and conveyor belts.

🎯 Exam Tip: Knowing the monomer unit for each polymer is crucial, as it defines the polymer's structure and properties.

Question 13. What is PHBV? How is it prepared? Mention its use.
Answer: PHBV stands for Poly-\(\beta\)-hydroxy butyrate-co-\(\beta\)-hydroxy valerate. It is a type of copolymer. This polymer is made from two different monomer units: 3-hydroxy butanoic acid and 3-hydroxy pentanoic acid. These monomer units are joined together by ester linkages during the polymerization process. PHBV has important uses in medicine, such as in orthopedic devices and for the controlled release of drugs, making it a valuable material in healthcare.
In simple words: PHBV is a special plastic made from two different types of acid molecules joined by ester links. It is used in medical devices and to release medicines slowly.

🎯 Exam Tip: When discussing biopolymers like PHBV, highlighting their biodegradability and biocompatibility is essential, as these are their key advantages.

Question 14. How is Nylon-2-Nylon-6 prepared?
Answer: Nylon-2-Nylon-6 is a type of copolymer. It is created through a condensation polymerization process. The specific monomers used to make this polymer are glycine and \(\epsilon\)-amino caproic acid. During the reaction, these molecules join together, and water molecules are eliminated, forming the long polymer chains of Nylon-2-Nylon-6. This method allows for the creation of unique polymers with diverse properties.
In simple words: Nylon-2-Nylon-6 is a plastic made by joining glycine and \(\epsilon\)-amino caproic acid. Water is taken out as they connect to form a long chain.

🎯 Exam Tip: For condensation polymers, always remember that a small molecule like water or HCl is usually removed during the formation of the polymer chain.

Question 1. How polymers are classified on the basis of structure and molecular formula and forces gives example one.
Answer: Polymers can be classified in different ways, including based on their structure, molecular formula, and the forces between their molecules. Here's a breakdown:
(A) Classification based on the structure of polymers:
(i) Linear polymers: These polymers have monomer units linked together to form a long, straight chain. An example is High-Density Polyethylene (HDPE) or Polyvinyl Chloride (PVC).
(ii) Branch chain polymers: In these polymers, a main chain has smaller chains branching off from it. Polypropylene and Low-Density Polyethylene (LDPE) are examples.
(iii) Crosslinked or Network polymers: These polymers have monomers linked together to form a complex three-dimensional network. This structure makes them very strong. Bakelite is a good example.
(B) Classification Based on Molecular Forces:
(i) Elastomers: These are soft, stretchy polymers, similar to rubber. Their chains are held by very weak forces, allowing them to stretch easily and return to their original shape. Buna-S and Neoprene are examples.
(ii) Thermoplastics: These polymers become soft when heated and harden when cooled. They can be molded and reshaped multiple times. Polythene, PVC, and Polystyrene are common thermoplastics.
(iii) Thermosetting: These polymers do not become soft when heated. Instead, they set into a hard, infusible mass and cannot be remolded once cured. Bakelite and melamine formaldehyde are examples.
(iv) Fibre: Fibres have strong forces between their molecules, leading to high tensile strength and less elasticity. Nylon-6,6 and Terylene are examples of polymers used as fibres.
In simple words: Polymers are grouped by how their parts are shaped (like straight lines, branches, or networks) and by how strong the links are between them. Some are stretchy like rubber, some melt when hot, and others stay hard no matter what.

🎯 Exam Tip: When classifying polymers, always provide a clear definition for each category and give at least one relevant example to illustrate your understanding.

Question 2. Explain various types of anaesthetics.
Answer: Anaesthetics are drugs that cause a loss of sensation. They can be divided into two main types: local anaesthetics and general anaesthetics. Each type works differently to prevent pain.
Local anaesthetics:
These drugs cause a loss of sensation only in the specific area where they are applied, without making the person lose consciousness. They work by blocking the pain signals from being sent through the nerves to the brain. Local anaesthetics are frequently used during minor surgical procedures. Examples include ester-linked local anaesthetics like Procaine, and amide-linked local anaesthetics like Lidocaine.
General anaesthetics:
These drugs cause a controlled and reversible loss of consciousness, affecting the entire central nervous system. They are typically used for major surgical procedures where the patient needs to be completely unconscious and unable to feel pain. Examples of intravenous general anaesthetics include Propofol, while Isoflurane is an example of an inhalational general anaesthetic.
In simple words: Anaesthetics are medicines that stop you from feeling pain. Local ones numb just a small part of your body while you are awake. General ones make you sleep deeply so you don't feel anything during big operations.

🎯 Exam Tip: When explaining drug types, always specify their primary effect, how they work (mechanism), and provide at least two common examples for each category.

Question 3. Explain about antimicrobials.
Answer: Antimicrobials are substances that kill or stop the growth of microorganisms like bacteria, fungi, and viruses. They are vital for treating infections and protecting health. Different types of antimicrobials work in specific ways.
Beta-Lactams:
These antimicrobials work by stopping bacteria from building their cell walls. This weakens the bacteria and eventually kills them. They are used to treat various infections, including skin infections, dental infections, ear infections, respiratory tract infections, pneumonia, urinary tract infections, and gonorrhoea. Examples include Penicillins, Ampicillin, and Cephalosporins.
Macrolides:
Macrolides target the ribosomes of bacteria, which are responsible for making proteins. By preventing protein production, these drugs stop the bacteria from growing and multiplying. They are used for respiratory tract infections, genital infections, gastrointestinal tract infections, and skin infections. Erythromycin and Azithromycin are common examples.
Fluoroquinolones:
These drugs inhibit a bacterial enzyme called DNA gyrase, which is essential for bacterial DNA replication and repair. By doing so, they prevent bacteria from reproducing. They are effective against urinary tract infections, skin infections, respiratory infections (such as sinusitis, pneumonia, bronchitis), and pulmonary infections like cystic fibrosis. Ciprofloxacin and Levofloxacin are examples.
Tetracyclines:
Tetracyclines work by stopping bacterial protein synthesis. They interfere with the 30S subunit of the bacterial ribosome, which is crucial for building proteins. These are used to treat peptic ulcers, respiratory tract infections, cholera, acne vulgaris, and other bacterial infections. Doxycycline, Minocycline, and Oxytetracycline are examples.
Aminoglycosides:
Similar to tetracyclines, aminoglycosides bind to the 30S subunit of the bacterial ribosome. This action stops bacteria from making essential proteins. They are primarily used to treat infections caused by gram-negative bacteria. Streptomycin, Neomycin, and Kanamycin are well-known aminoglycosides.
In simple words: Antimicrobials are medicines that fight tiny living things like bacteria and fungi. They work in different ways, like stopping bacteria from building walls or making proteins, to cure infections in your body.

🎯 Exam Tip: When explaining antimicrobials, focus on their mechanism of action (how they work) and mention the specific types of infections they treat, along with relevant examples.

Question 4. Explain the steps involved in free radical polymerisation.
Answer: Free radical polymerization is a process where many small molecules (monomers) join together to form a long chain (polymer) using highly reactive free radicals. This process typically happens when alkenes are heated with a free radical initiator, like benzoyl peroxide. It involves three main steps:
1. Initiation – Formation of free radical:
This step starts the process. The initiator molecule breaks apart to form free radicals, which are very reactive species with an unpaired electron. For example, benzoyl peroxide breaks down to form phenyl free radicals and carbon dioxide.
2. Propagation step:
In this step, the free radical adds to a monomer molecule, creating a new, larger free radical. This new radical then adds to another monomer molecule, and the chain grows rapidly. This continuous addition of monomers makes the polymer chain longer.
3. Termination:
The chain growth stops when two free radical chains combine or when a free radical reacts with an impurity. This step ends the polymerization process by forming stable polymer molecules.
In simple words: Free radical polymerization happens in three steps: first, tiny very active particles (free radicals) are made. Second, these particles link to small chemical units, making longer chains. Third, the chains stop growing when they meet another active particle or something else.

🎯 Exam Tip: Clearly defining each step (initiation, propagation, termination) and explaining the role of free radicals is key to scoring full marks on questions about free radical polymerization.

Question 5. Write about buna rubbers.
Answer: Buna rubbers are synthetic rubbers known for their toughness and resistance to oil and heat. They are created through a process called copolymerization, where two different types of monomers join together to form the polymer chain. These rubbers are very versatile and are used in various industrial applications due to their durability.
Buna-N:
Buna-N is a type of copolymer. The monomers used to make Buna-N are acrylonitrile and buta-1,3-diene. This polymerization process is typically initiated with a sodium catalyst. Buna-N is commonly used in the manufacture of hoses and tank linings because of its excellent resistance to oils and solvents.
In simple words: Buna rubbers are man-made rubbers that are tough and resist oil. Buna-N is made from acrylonitrile and buta-1,3-diene, often with a sodium catalyst. It's used for hoses and tank parts because it doesn't get damaged by oil.

🎯 Exam Tip: For copolymer questions, ensure you list both specific monomers involved and the key properties or uses that result from their combination.